Guitar Hero: World Tour Easter Eggs

Guitar hero seems to "hide" songs in their game in little pictures throughout their games.

Cherry Pie - In Guitar Hero 2, on the loading screen on the top right, there is a cherry on a stick, and the mathematical symbol for PI.

3s & 7s - In Guitar... more

If you play any gig in Times Square,
(the one where you are on top of the building)
There will be a lot of posters/billboards around.

If you look at one of them,
(there's more than one of these)
one will say
"From the skateboard... ...to the... more